I bought some today hoping they would work. They have 700mb each and I was strangely able to put about 50 - 60 songs. (I usually can put 20)

I burned the songs using WMP, was done, went to the car to see if they work, and it didn't.

now what
Yeah, I thought I was, but I burned the songs the exact way I did when I used those crappy maxell cd's. and those worked with my stereo.
you should have bought microsoft brand, sony sucks
im joking of course sony rules
and you probally did input data and not music, so try again